Partly that the work may not be hindered, and partly for the security of thy own person. See 2 Kings 9:3.
Related Commentaries of 2 Kings 9:2
2 Kings 9:2
2 And when thou comest thither, look out there Jehu the son of Jehoshaphat the son of Nimshi, and go in, and make him arise up from among his brethren, and carry him to an innera chamber;